Proliferation of smart phones, and their subsequent use to perform high data-rate communication, has resulted in an exponential growth in the volume of data flowing over wireless networks. The increased volume of data flowing over the networks is taxing the service providers and the legacy network infrastructure responsible for ensuring the data reliably flows for most, if not all, users.
Furthermore, the introduction of a new generation of mobile wireless networks based upon 3GPP Release 8 and later mobile wireless standards (e.g., fourth generation Long Term Evolution “4G LTE”) and associated communications infrastructure has indeed substantially increased the throughput capabilities of mobile wireless networks for users that subscribe to and use 4G services. Thus, the newest generation of mobile wireless network technologies has created increasingly high expectations by users with regard to both reliability and quality of service of mobile wireless networks. The high degree of reliability achieved by mobile wireless services has resulted in many mobile wireless subscribers foregoing conventional landline voice and/or data network services. Such subscribers rely wholly upon mobile wireless service to meet their communication needs.
Given the increased expectations and reliance of subscribers on mobile wireless network services, it is imperative for the underlying mobile wireless network infrastructure to be properly maintained. When parts of the mobile wireless network infrastructure are unable to adequately support subscriber needs and expectations at particular locations in the network, such parts (e.g., cell sites or portions thereof) must be quickly identified and remedial action taken. Thereafter, the cause(s) of the identified performance failure need to be identified and addressed. However, identifying the cause of poor data transmission service and the remedy for the poor service is not a trivial endeavor.
To address the above needs, operators deploy LTE technology using multiple frequency layers, also referred to as “channels.” Each layer is specified by a 3GPP Release 8 (or newer) Frequency Band consisting of a specified center operating frequency as well as a configured bandwidth for the individual (sub)channels within the general frequency band. In view of the presence of multiple supported frequency layers, the 3GPP Release 8 (and newer) standards specify/define a procedure and a parameter setting, referred to herein as an absolute frequency layer priority. The absolute frequency layer priority setting is provided by a radio access node (e.g. an eNodeB macrocell) to a User Equipment (UE) device, such as a smartphone mobile wireless device, within range of the radio access node seeking to connect to a cell/sector associated with the radio access node. The absolute frequency layer priority setting specifies values indicating a recommended order of preference for selecting one of the supported frequency layers when connecting to the radio access node. In known radio access networks, the absolute frequency layer priorities are assigned manually and do not change unless manually re-configured by the radio access network service provider.
The current disclosure is directed to examples relating to LTE mobile wireless networks, and more particularly the ability to assign particular priorities to specific frequency layers for LTE eNodeB macrocells. This setting is a control information element (IE) consulted by UEs during a LTE Cell Reselection event. Per the LTE standard, a UE selects a requested frequency layer, on which to attempt establishing a connection via a radio link with an eNodeB cell, based on absolute radio frequency layer priorities assigned to the respective radio frequency layers for that eNodeB cell. In the case of LTE technologies, the priorities can be set anywhere within a range of 0 to 7, with 7 being the highest priority. Multiple cells (also referred to as “sectors” in non-LTE radio access link technologies) may overlap and therefore cover a same (overlapped) geographical area, and the cells and/or sectors may have the same or different absolute frequency priority assignments.
According to the 3GPP release 8 and the LTE standard, the absolute frequency priority setting is considered during: (1) inter-frequency cell reselection, (2) idle mode mobility control info, and (3) redirected carrier events. During inter-frequency cell reselection events, UEs access an absolute frequency priority IE from a provided System Information Block 5 (SIB5) that contains cell reselection parameters for inter-frequency cell reselection. Thereafter, the UEs compare the absolute frequency priorities from SIB5 to the absolute frequency priority configured on the currently serving frequency layer as indicated in System Information Block 3 (SIB3)—Cell Selection and Cell Reselection Parameters for Intra-frequency events. The comparison is used to determine whether the steps for inter-frequency cell reselection should be initiated on the UE—if the currently serving frequency layer has a lower priority than a priority value of another layer specified in SIB5.
In other scenarios, idle mode mobility control information and redirected carrier events cause initiation of operations on UEs that consult the absolute frequency layer priority setting of a cell/sector to initiate inter-frequency cell reselection event following a Radio Resource Control (RRC) Connection Release message used to manage airlink access resources. The RRC Connection Release message may contain a list of frequency layers and their assigned priority values as IEs to be considered for inter-frequency cell reselection during idle mode mobility. This same RRC Connection Release message can specifically contain the redirected carrier information IE specifying radio frequency layer priority values by Evolved Absolute Radio Frequency Channel Number (EARFCN) upon which the UE should rely to perform cell reselection following an RRC Connection Release.
In an LTE environment, an Absolute Frequency Priority (AFP) IE is contained in: (1) a System Information Block 3 “SIB3” (Intra-frequency information) message; (2) a System Information Block 5 “SIB5” (Inter-frequency information) message; and (3) an RRC Connection Release Idle Mode Mobility Information with associated EARFCN message. The AFP IE is considered for RRC Connection Release Redirected Carrier Frequency IE (for this redirection, the EARFCN is the indicated IE based on its priority). Moreover, the absolute priority, when specified in each of the above-described message types, is specified by an integer value between zero (0) and seven (7), with zero being the lowest and seven being the highest priority. Priorities are assigned to frequency layers at an eNodeB cell level of granularity, and can have equal or different assigned values at the various levels.
In the known LTE environment an authenticated UE within LTE coverage can be in either an RRC-Connected state or an RRC-IDLE state. In the case of the UE in RRC-Idle state, system information is considered for frequency assignment, including SIB3 and SIB5 information (i.e., absolute frequency layer priority values are indicated). In the case of the UE in an RRC-Connected Mode, cell reselection is driven by RRC Connection Release event messaging. During the cell reselection redirected carrier information provides direction to selection of other specific frequency layer EARFCN (rule is set based on absolute frequency priority setting). Moreover, idle mode mobility information indicates available radio frequency layer (EARFCN) choices and associated absolute priorities to consider for UE measurement reporting and possible cell reselection.
Importantly, radio frequency layer priority configurations are relatively static and require manual intervention to change. Direct operator action is needed to carry out modifying absolute frequency priorities.